An image forming apparatus configured to receive a service provided by a service providing apparatus on Internet is conventionally known. The service provided by the service providing apparatus includes, for example, a service of storing data uploaded by an image forming apparatus in the service providing apparatus, a service of downloading data stored in the service providing apparatus to the image forming apparatus, and so on. For example, a known image forming apparatus transmits authentication information to a Web server for receiving authentication, and receives content data from the Web server.